CVE-2026-56818

Netty: RedisArrayAggregator max-elements failure leaves retained partial aggregate state

Published Aug 7, 2026 CVSS 3.1 · 6.5 Medium EPSS < 1% KEV · Not listed
Description
Netty is an asynchronous, event-driven network application framework. Prior to 4.1.136.Final and 4.2.16.Final, the RedisArrayAggregator Redis codec clears retained partial aggregate state when the maxNestedArrayDepth limit is exceeded, but it does not clear the same state when the sibling maxElements limit is exceeded. A peer can start a valid RESP array, send a bulk string child, then send a nested array header longer than the configured maxElements. Netty throws a decoder exception in decodeRedisArrayHeader, but the existing partial aggregate remains retained in the handler. If the application leaves the channel alive after the exception, later messages are still consumed into the pre-error aggregate, allowing an unauthenticated peer to keep attacker-controlled aggregate state alive across a security-limit exception and pin retained pooled buffers. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-p9jm-q85p-7mcp Netty: RedisArrayAggregator max-elements failure leaves retained partial aggregate state
History
Type Values Removed Values Added
First Time appeared Netty
Netty netty
CPEs cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*
Vendors & Products Netty
Netty netty
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description A flaw was found in the Netty `netty-codec-redis` component. This vulnerability allows a remote attacker to cause a denial of service (DoS) by sending specially crafted Redis protocol frames over long-lived connections. The Redis decoder fails to properly release allocated memory, leading to memory exhaustion and application instability. Netty is an asynchronous, event-driven network application framework. Prior to 4.1.136.Final and 4.2.16.Final, the RedisArrayAggregator Redis codec clears retained partial aggregate state when the maxNestedArrayDepth limit is exceeded, but it does not clear the same state when the sibling maxElements limit is exceeded. A peer can start a valid RESP array, send a bulk string child, then send a nested array header longer than the configured maxElements. Netty throws a decoder exception in decodeRedisArrayHeader, but the existing partial aggregate remains retained in the handler. If the application leaves the channel alive after the exception, later messages are still consumed into the pre-error aggregate, allowing an unauthenticated peer to keep attacker-controlled aggregate state alive across a security-limit exception and pin retained pooled buffers. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.
Title io.netty/netty-codec-redis: Netty: Memory leak in netty-codec-redis Netty: RedisArrayAggregator max-elements failure leaves retained partial aggregate state
Weaknesses CWE-401
CWE-703
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L'}

Type Values Removed Values Added
Description A flaw was found in the Netty `netty-codec-redis` component. This vulnerability allows a remote attacker to cause a denial of service (DoS) by sending specially crafted Redis protocol frames over long-lived connections. The Redis decoder fails to properly release allocated memory, leading to memory exhaustion and application instability.
Title io.netty/netty-codec-redis: Netty: Memory leak in netty-codec-redis
Weaknesses CWE-772
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Important

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Aug 8, 2026, 3:01 AM
Reserved
Jun 23, 2026, 2:55 PM
Status
Analyzed
Published
Aug 7, 2026, 6:17 PM
Modified
Sep 23, 2026, 3:56 PM
Severity
Important
Public date
Jul 9, 2026, 12:00 AM